9.4 Genetic Engineering

KEY CONCEPT

Genetic Engineering is about changing the DNA

sequences of organisms.

9.4 Genetic Engineering

Genetic Engineering Technique #1:

Entire organisms can be cloned.

• A clone is a genetically identical copy of a gene or of

an organism.

CC, short for Copy

Cat, is the first

successfully cloned

Cat.

The original

cat

9.4 Genetic Engineering

• Cloning occurs in nature.

– bacteria (binary fission)

– some plants (from roots)

– some simple animals (budding, regeneration)

9.4 Genetic Engineering

• Mammals can be cloned through a process called nuclear

transfer.

– nucleus is removed from an egg cell

– nucleus of a cell from the animal to be cloned is

implanted in the egg

9.4 Genetic Engineering

One of first mammals to be successfully cloned was a sheep.

9.4 Genetic Engineering

The adult sheep is Dolly,

the first mammal cloned

from an adult cell.

The lamb is Dolly’s

offspring, called Bonnie.

9.4 Genetic Engineering

• Cloning has potential benefits.

– organs for transplant into humans

– save endangered species

• Cloning raises concerns.

– low success rate

– clones “imperfect” and less healthy than original animal

– decreased biodiversity

9.4 Genetic Engineering

Genetic Engineering Technique #2: Recombinant DNA

New genes can be added to an organism’s DNA.

• Genetic engineering involves changing an organism’s

DNA to give it new traits.

• Genetic engineering is based on the use of

recombinant DNA.

• Recombinant DNA contains genes from more than

one organism.

(bacterial DNA)

9.4 Genetic Engineering

• Process involves:

– Bacterial plasmids are often used to make

recombinant DNA.

– Steps:

1. plasmids are loops of

DNA in bacteria

2. restriction enzymes cut

plasmid and foreign DNA

3. foreign gene inserted

into plasmid

9.4 Genetic Engineering

Genetic Engineering Technique #3: GMO’s

A GMO = a “Genetically Modified Organism”

• A “GMO” or transgenic organism has one or more

genes from another organism inserted into its genome.

9.4 Genetic Engineering

• GMO (Transgenic) bacteria can be used to produce

human proteins.

– gene inserted into plasmid

– plasmid inserted into bacteria

– bacteria express the gene

• GMO (Transgenic) plants are common in agriculture.

– transgenic bacteria

infect a plant

– plant expresses

foreign gene

– many crops are now

genetically modified

(GM)

9.4 Genetic Engineering

Examples of how transgenic bacteria and plants are

being used:

1. Transgenic Bacteria

Now make insulin, growth hormone, and clotting

factor cheaply and in great abundance)

2. Transgenic Plants

52% of soybeans and 25% of corn are transgenic

Different varieties are resistant to disease,

produce their own insecticide, resist weed-killing

chemicals, and/or have increased vitamin content

9.4 Genetic Engineering

• GMO (Transgenic) animals are used to study

diseases and gene functions.

– Ex. transgenic mice used to study development

and disease

– gene “knockout mice” used to study gene function

Knockout mouse on left lacks gene for protein leptin,

which helps to control food intake. Used in obesity studies.

9.4 Genetic Engineering

• Can Genetic Engineering be used to bring back extinct

species or save endangered species?

https://www.youtube.com/watch?v=68QhIQLeVUA

9.4 Genetic Engineering

• Cloning: National Geographic Video

• http://www.youtube.com/watch?v=dfqwUlnsGvY

9.4 Genetic Engineering

• Scientists have concerns about some uses of genetic

engineering.

– possible long-term health effects? of eating GM foods

– possible effects of GM plants on ecosystems and

biodiversity ?

9.4 Genetic Engineering

Place in Science Fiction

• Jessica Alba as “Max” in the SciFi TV series

“Dark Angel”